Beril Bicer-Simsir (left) GCI assistant scientist, and Giorgio Torraca, conservation scientist, testing injectability device, which assesses the degree of ease with which a grout can be injected through a column of crushed brick, travertine, or sand. Photo: Leslie Rainer.

In most cases standardized tests, including ASTM, DIN, EN, UNI, among others, have been developed for portland cement–based mortars and grouts, but not specifically for injection grouts used in the conservation of architectural surfaces that are mostly lime- or hydraulic lime-based. The team identified existing test methods for mortars and grouts, evaluated the properties under investigation and grouped them under four areas. In some cases, more than one standard test method was evaluated for determining a specific property of the hydraulic-lime based injection grouts. The test methods examined in this study are as follows:

The tensile strength of a grout is estimated through an indirect tensile test called splitting tensile test (Brazilian Test). The test is carried out on cylinders with an aspect ratio of 1:2 and tested on its side in diametral compression. Photo: Beril Bicer-Simsir.

The grouts were selected to provide a wide range of working and performance properties to evaluate the effectiveness of test methods and for their availability and common use in the field.

Commercial and custom-mixed grouts are undergoing a series of tests, such as this one to determine water vapor permeability, to assess the working properties and performance characteristics of different grout formulations. Photo: Hande Cesmeli.

STAGE 3: Determination of modifications to existing testing protocols
Many standard tests are not immediately suitable for testing injection grouts used in the conservation of architectural surfaces. When possible, existing standard test methods were modified and adapted for this purpose.

STAGE 4: Development of new test methods
Project team developed laboratory and field test methods when no tests were available to evaluate specific properties of injection grouts or when modifications to existing methods were not found to be satisfactory.

STAGE 5: Compilation and publication of Evaluation of Lime-Based Hydraulic Injection Grouts for the Conservation of Architectural Surfaces
Based on the testing development carried out, the project team prepared a series of test methods for laboratory and field use.